. General physiology; an outline of the science of life. STIMULI AND THEIR ACTIONS 425 between the individual stimuli to be recognised clearly (Fig. 207, II). If induction-shocks be allowed to act upon the muscle in more rapid succession, as they are produced in the secondary coil by the play of Neef's hammer, the effect of each single shock is no longer to be distinguished as such, but a smooth curve results, which rises rather steeply and then, if the stimulation be not con- tinued too long, maintains itself at a uniform height as a straight line (Fig. 207, ///). Thus, by increasing the rate
. General physiology; an outline of the science of life. STIMULI AND THEIR ACTIONS 425 between the individual stimuli to be recognised clearly (Fig. 207, II). If induction-shocks be allowed to act upon the muscle in more rapid succession, as they are produced in the secondary coil by the play of Neef's hammer, the effect of each single shock is no longer to be distinguished as such, but a smooth curve results, which rises rather steeply and then, if the stimulation be not con- tinued too long, maintains itself at a uniform height as a straight line (Fig. 207, ///). Thus, by increasing the rate of succession of the stimuli, it is possible to follow the formation of complete tetanus from the completely finished single contractions through all the transition-forms of incomplete tetanus, and thereby to afford the proof that, in reality, tetanus is a discontinuous con-. FlG. 206.—iluscle-writer. The nerve-muscle preparation is fixed in the muscle-holder ; the nerve is stinuilated by pointed platinum electrodes ; and the muscle records its movement upon a rotating, blackened drum by means of a writing-lever. traction. All continued contractions that are performed in the human body under nervous influence are, like tetanus artificially produced, discontinuous phenomena composed of many single contractions following one another in rapid succession. It should be mentioned that there are forms of living substance that are not influenced at all by induction-shocks, either b}' single ones or by shocks succeeding one another rapidly or slowly, however strong they may be. Such objects are Orhitolites, Amphistegina, and other marine Rhizopoihi. Their protoplasm requires for reaction a longer duration of the stimulus than the lightning-like induction-shock possesses.^ As regards other excitation-effects of galvanic stimulation, mechanical motile effects are produced, not only in contractile 1 Cf. A'erworn {'92, 2).. Please note that these images are extracted from scanned page im
Size: 1656px × 1509px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookauthorverwornmax18631921, bookcentury1800, bookdecade1890
